Method for preparing boron nitride nanotubes

Abstract

Provided is a method for preparing boron nitride nanotubes, the method including: injecting a boron-metal catalyst composite into a reaction chamber; injecting a nitrogen precursor into the reaction chamber; producing a decomposition product of the boron-metal catalyst composite in a gas state by irradiating the boron-metal catalyst composite with a carbon dioxide laser or a free electron laser; and forming boron nitride nanotubes by reacting the decomposition product of the boron-metal catalyst composite in the gas state with the nitrogen precursor.

What is claimed is: 
     
       1. A method for preparing boron nitride nanotubes, the method comprising:
 injecting a boron-metal catalyst composite into a reaction chamber; 
 injecting a nitrogen precursor into the reaction chamber; 
 producing a decomposition product of the boron-metal catalyst composite in a gas state by irradiating the boron-metal catalyst composite with a carbon dioxide laser or a free electron laser; and 
 forming boron nitride nanotubes by reacting the decomposition product of the boron-metal catalyst composite in the gas state with the nitrogen precursor, wherein the boron nitride nanotubes comprise a metal catalyst, and 
 etching the metal catalyst from the boron nitride nanotubes by using an etchant, 
 wherein a ratio of single-walled boron nitride nanotubes and double-walled boron nitride nanotubes in the boron nitride nanotubes is 70 wt % to 99.9 wt %. 
 
     
     
       2. The method according to  claim 1 , wherein the boron-metal catalyst composite further comprises a solid precursor comprising a nitrogen atom. 
     
     
       3. The method according to  claim 1 , wherein the injecting of the nitrogen precursor into the reaction chamber is carried out under a pressure condition of 1 atm to 300 atm. 
     
     
       4. The method according to  claim 1 , wherein
 the etchant comprises any one selected from the group consisting of ammonium persulfate, a nickel etchant, a copper etchant, iron chloride (FeCl 3 ), nitric acid, hydrochloric acid, and sulfuric acid. 
 
     
     
       5. The method according to  claim 4 , wherein the metal catalyst comprises one or more selected from the group consisting of nickel (Ni), copper (Cu), iron (Fe), chromium (Cr), cobalt (Co), zinc (Zn), aluminum (Al), silicon (Si), scandium (Sc), titanium (Ti), vanadium (V), manganese (Mn), gallium (Ga), germanium (Ge), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), bronze, stainless steel, white brass, brass, and a combination thereof. 
     
     
       6. The method according to  claim 5 , wherein the metal catalyst comprises iron metal catalyst. 
     
     
       7. The method according to  claim 1 , wherein the boron nitride nanotubes are prepared so as to have an average internal diameter of 1 nm to 10 nm. 
     
     
       8. The method according to  claim 1 , wherein the metal catalyst is included within a range of 0.01 wt % to 80 wt % based on a total weight of boron. 
     
     
       9. The method according to  claim 8 , wherein the metal catalyst is included within a range of 0.01 wt % to 10 wt % based on a total weight of boron. 
     
     
       10. The method according to  claim 1 , wherein etching the metal catalyst from the boron nitride nanotubes comprises using ammonium persulfate. 
     
     
       11. The method according to  claim 1 , wherein etching the metal catalyst from the boron nitride nanotubes comprises using a nickel etchant. 
     
     
       12. The method according to  claim 1 , wherein etching the metal catalyst from the boron nitride nanotubes comprises using a copper etchant. 
     
     
       13. The method according to  claim 1 , wherein etching the metal catalyst from the boron nitride nanotubes comprises using iron chloride (FeCl 3 ). 
     
     
       14. The method according to  claim 1 , wherein etching the metal catalyst from the boron nitride nanotubes comprises using hydrochloric acid. 
     
     
       15. The method according to  claim 1 , wherein etching the metal catalyst from the boron nitride nanotubes comprises using sulfuric acid. 
     
     
       16. A method for preparing boron nitride nanotubes, the method comprising:
 injecting a boron-metal catalyst composite into a reaction chamber; 
 injecting a nitrogen precursor into the reaction chamber; 
 producing a decomposition product of the boron-metal catalyst composite in a gas state by irradiating the boron-metal catalyst composite with a carbon dioxide laser or a free electron laser; and 
 forming boron nitride nanotubes by reacting the decomposition product of the boron-metal catalyst composite in the gas state with the nitrogen precursor, 
 wherein a ratio of single-walled boron nitride nanotubes and double-walled boron nitride nanotubes in the boron nitride nanotubes is 70 wt % to 99.9 wt %, and 
 wherein the boron-metal catalyst composite comprises a pure boron fiber and a metal catalyst deposited onto the pure boron fiber. 
 
     
     
       17. The method according to  claim 16 , wherein the metal catalyst is deposited by a deposition device comprising one or more selected from the group consisting of a deposition device using e-beam, a sputtering deposition device, an electroplating device, and an electroless plating device. 
     
     
       18. A method, the method comprising:
 injecting a boron-metal catalyst composite into a reaction chamber, wherein the boron-metal catalyst composite is a mixture of a pure boron powder and a metal catalyst; 
 injecting a nitrogen precursor into the reaction chamber; 
 producing a decomposition product of the boron-metal catalyst composite in a gas state by irradiating the boron-metal catalyst composite with a carbon dioxide laser or a free electron laser; and 
 forming boron nitride nanotubes by reacting the decomposition product of the boron-metal catalyst composite in the gas state with the nitrogen precursor, 
 wherein a ratio of single-walled boron nitride nanotubes and double-walled boron nitride nanotubes in the boron nitride nanotubes is 70 wt % to 99.9 wt %. 
 
     
     
       19. The method according to  claim 18 , wherein the metal catalyst comprises one or more selected from the group consisting of nickel (Ni), copper (Cu), iron (Fe), chromium (Cr), cobalt (Co), zinc (Zn), aluminum (Al), silicon (Si), scandium (Sc), titanium (Ti), vanadium (V), manganese (Mn), gallium (Ga), germanium (Ge), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), bronze, stainless steel, white brass, brass, and a combination thereof. 
     
     
       20. The method according to  claim 19 , wherein the metal catalyst comprises iron metal catalyst.